Production of synthetic resins



Patented Jan. 24, 1939 PRODUCTION OF SYNTHETIC RESINS Adolf Hodler, Ludwigshafen-on-the-Rhine, Germany, assignorto I. G. Farbenindustrie Aktiengesellschaft, Frankfort-on-the-Main, Germany No Drawing. Application March 9, 1937, Serial No. 129,815. In Germany March 28, 1936 8 Claims. (cl. 260-72) The present invention relates to a process of producing synthetic resins.

It has already been proposed to condense aliphatic aldehydes, as for example acetaldehyde,

aldol, crotonaldehyde and the like, in the presence of primary or secondary amines to form a mixture of oils and resins. The resins thus obtained have, however, disadvantages, as for example sticking when polished, dark color, disl0 appearance of the lustre and comparatively slight resistance to water, which impair their use in practice. I

I have now found that valuable synthetic resins areobtained by condensing aliphatic alde-' hydes containing from 2 to 4 carbon atoms by means of small amounts of primary or secondary alkylamines or aralkylamines or secondary heterocyclic bases or their salts with weak acids as catalyst, the resulting resinous products being treated with formaldehyde or substances yielding formaldehyde, if desired in the presence 'of' oxidizing agents, at temperatures of up to 250 C. before, duringor after distilling off of the readily volatile oils simultaneously formed. The treatment with formaldehyde or agents yielding formaldehyde may also be effected with said aldehyde resins which have already been subjected to an improving treatment, as for example a treatment with organic acids or inorganic halides having a condensing action, the concentration of the oxidizing agents which may be present should be selected so that for each molecular proportion of formaldehyde there is present at the most 1 molecular proportion of oxidation oxygen.

In spite of the use of oxidizing agents no burn ing or dark coloration takes place in the presence of excess of formaldehyde, even at high temperatures, but on the contrary a considerable lightening in color and improvement of the resin takes place. l

As aliphatic-aldehydes containing from 2 to 4 carbon atoms may be mentioned acetaldehyde, aldol, crotonaldehyde or mixtures of these with each other. Small amounts of other organic substances, such as alcohols, in particular polyhydric alcohols, ketones, as for example acetone or diacetyl, ketone or hydroxyacids, esters or resin acids, such as colophony or the various abietic acids contained therein may be condensed together with the said aldehydes. Primary or secondaryalkylamines, aralkylamines or secondary heterocyclic bases or their salts with weak acids suitable for the present process are for example methylamine, ethylamine, butylthe formaldehyde.

amine, benzylamine and the corresponding diamines or piperidine as well as their salts with acetic acid, propionic .acid, butyric acid, gly-' colic and lactic acid.

As oxidizing agents there may be mentioned in 5 particular peroxides, as for example hydrogen peroxide, benzoylperoxide, peracetic acid, sodium persulphate. Air or ,oxygen may, however, also be used as oxidizing agents, for example by allowing them to act on the resins together with The oxidizing agents and the formaldehyde or substances yielding form aldehyde, such as paraformaldehyde and hexamethylene tetramine, may be used in the vapour phase or in dissolved form and the resin to be 15 treated may be in the fused or dissolved form. The products thus. obtained have especially good properties. They are clear, transparent and of excellent hardness. They are readily soluble to give clear solutions in most resin and 20 lacquer solvents and thus have in practice a great number of uses. For example alone or to gether with nitrocellulose they yield entirely transparent, solid films. Alone Or in admixture with nitrocellulose they may be polished simi- 2 larly to shellac and yield an excellent, highly lustrous, extremely hard and stable polish. They may therefore be used instead of shellac. By reason of the fact that the treatment with formaldehyde is usually attended by a lightening in 30 the color, they are also suitable as polishing agents for quite pale types of wood. The products are also soluble in drying oils, as for example linseed oil, and yield clear and hard films with the same. 5

The following examples will further illustrate how the present invention may be carried out in practice but the invention. is not restricted to these examples. Theparts are by Weight. 40

' Example 1 boiled for 2 hours at C. After cooling the crude resinous condensation product is separated from the water formed and treated for two hours 50 g at 100 C. with 295 parts of 30 per cent aqueous formaldehyde solution. After removingthe aqueous and oily fractions by distilling the mixture up to 220 0., there remain 400 parts of hard resin. This is readily soluble in alcohol and 5 by polishing yields polishes of excellent hardness and excellent gloss.

Example 2.

700 parts of acetaldehyde are stirred into a mixture of 450 parts of water, 15 parts of acetoacetic acid ester, 43 parts of diethylamine and 75 parts of abietinol and heated for hours at 100 C. Water and small amounts of oil s1- multaneously formed are distilled off by heating -to 220 C. After cooling, the resulting resinous crude product is treated for an hour with 190 parts of aqueous 30 per cent fomaldehyde solution. The constituents of low boiling point present are distilled off by a repeated heating to 220 C. 390 parts of pale, hard resin remain as Example 3 750 parts of acetaldehyde are slowly introduced into a mixture of 500 parts of water, 40 parts of abietinol, 40 parts of glycerine and 45parts of diethylamine. The mixture is then treated further as described in Example 1. The crude resinous condensation product obtained is boiled with 65 parts of anhydrous formic acid for half an hour. The readily volatile constituents are distilled off while heating up to 220 C. 500 parts of a darkyellow resin are thus obtained. This resin is treated for 4 hours at 100 C. with 150 parts of 30 per cent formaldehyde solution. After separating the aqueous and oilyconstituents by heating to 220 0., there remain 4'70 parts of a pale, amber-colored, clear, transparent resin having a softening point of 73 C; The resin is harderand paler than the above resin having a softening point of 63 C. It dissolves in alcohol giving a pale yellow coloration and yields there- 'from, when polished on pale wood, excellent, en-

tirely pale, hard polishes of high lustre.

Example 4 705 parts of acetaldehyde are slowly introduced intoa mixture of 100 parts of a 50 per cent-aque-- ous glycerine solution, 15 parts of aceto-acetic acid ethyl ester and- 42 parts of diethylamine. The mixture is boiled under reflux for 5 hours. After cooling the reaction product is separated from ,the water and treated with 78 parts ofanhydrous formic acid for half an hour at 100 C. The readily volatile constituents are distilled ofl while heating up to 250 C. Gaseousformaldehyde is then led in at the same temperature at the rate of 0.25 part per minute for an hour. In this. way 460 parts of a pale resin are obtained which in alcoholic solution either alone or in conjunction with nitrocellulose is eminently suitable for polishing and yields polishes of high gloss and great hardness.

Example 5 783 parts of vapors of acetaldehyde are led into a mixture of 500 parts of waterand 43 parts of piperidine. The crude resinous condensation product obtained after boiling the mixture for 5 hours is freed from the readily volatile constituents by heating up to 220 C. and treated for 1 hour with vapors of formaldehyde, 0.8 part each minute. 480 parts of a resin are obtained which dissolves readily in alcohol and is capable of being polished either alone or in combination with nitrocellulose.

. Example 6 60 parts of vapors of formaldehyde diluted with nitrogen are introduced in the course of 1 hour at 200 C. into 2400 parts of a fused resin obtained by boiling a mixture of 3800 parts of acetaldehyde and 200 parts of diethylamine under reflux for 2 hours, treating the resulting condensation product with 400 parts of formic acid for half an hour at 100" C. and distilling off the volatile constituents while heating up to 220 C. 2400 parts of a pale, hard resin having a softening point of 71 C. are obtained. The resin is soluble in alcohol and capable of being polished like shellac, either alone or in combination with nitrocellulose.

Example 7 2440 parts of acetaldehyde are slowly introduced into 280 parts of a 50 per cent aqueous solution of diethylamine and the whole is boiled under reflux for 2 hours. After cooling, the resulting resinous condensation product is separated from the water and freed from the volatile constituents by heating up to 110 C. A mixture of vapors of 30 parts of formaldehyde and 50 parts of formic acid are blown in in the course of 1 hour while increasing the temperature from 110" to 220 C. a

620 parts of a pale, hard resin are thus obtained. It is capable of being polished yielding polishes of high lustre.

When employing monomethylamine, dimethy'lamine, dibutylamine or benzylamine or their salts with weak acids as condensing agents instead of diethylamine resins having similar properties are 1 obtained.

Example 8 800 parts of a resin still containing water (which has been prepared by boiling a mixture of 2440 parts of acetaldehyde and 140 parts of diethylamine in aqueous solution under reflux for 2 hours and removing the major portion of the water) are boiled for an hour with ermixture of 56 parts of a 20 per cent aqueous solution of hydrogen. peroxide and 55 parts of a 30 per cent aqueous solution of formaldehyde under reflux.

The wholeis then heated to 220 C. while distilling off the fraction of low boiling point, a mixture of a further 56 parts of the hydrogen peroxide solution and 88 parts of the formaldehyde solution being simultaneously introduced into the resin melt.

420 parts of a pale resin are obtained which is well soluble in alcohol and nitrocellulose solutions and which is eminently capable of being polished either alone or together with nitrocellulose.

Example 9 cent solution of hydrogen peroxide, for another hour. After separating the major portion of the water, the constituents of low boiling point still 75 present (the remainder of the water and oils) are distilled off up to 250 C. while at the same time there is added a mixture of 330 parts of an aqueous 30 per cent formaldehyde solution and 100 parts of an aqueous 30 per cent hydrogen peroxide solution.

1260 parts of a pale resin are obtained which is eminently capable of being polished for ex ample together with nitrocellulose.

What I claim is:

1. A process of producing synthetic resins, which comprises condensing aliphatic aldehydes containing from 2 to 4 carbon atoms by means of small amounts of a substance of the group of primary and secondary alkyl and aralkylamines, secondary heterocyclic bases and their salts with weak acids as catalyst and treating the resulting resinous products with formaldehyde at temperatures of up to 250 C.

2. A process of producing synthetic resins, which comprises condensing aliphatic aldehydes containing from 2 to 4 carbon atoms in admixture with a polyva-lent alcohol by means of small amounts of a substance of the groups of primary and secondary alkyl and aralkylamines, secondary heterocyclic bases and their salts with weak acids as catalyst and treating the resulting resinous products with formaldehyde at temperatures of up to 250 C. Y

3. A process of producing synthetic resins,

which comprises condensing aliphatic aldehydes ocyclic bases and their salts with weak acids as catalyst and treating the resulting resinous products with formaldehyde at temperatures of up to 250 C.

4. A process of producing synthetic resins, which comprises condensing aliphatic aldehydes containing from 2 to 4 carbon atoms by means of a substance of the group of primary and secondary alkyl and aralkylamines, secondary heterocyclic bases and their salts with weak acids and treating the resulting resinous products with formaldehyde and an oxidizing agent at temperatures of up to 250 C.

5. A process of producing synthetic resins, which comprises condensing aliphatic aldehydes containing from 2 to 4 carbon atoms by means of small amounts of diethylamine as catalyst and treating the resulting resinous products with formaldehyde at temperatures of up to 250 C.

6. A process of producing synthetic resins, which comprises condensing aliphatic aldehydes containing from 2 to 4 carbon atoms by means of diethylamine and treating the resulting resinous products with formaldehyde and hydrogen perox'i'de at temperatures of up to 250 C.

'7.Synthetic resins obtained according to the process of claim 1, said resins being soluble in process of claim 5, said resins being soluble in alcohol and being capable of taking a polish similar to shellac.

ADOLF HODLEH. 

